I too was confused about the location of the IR transmitter(s) on the SR80. I fired up my digital camera and aimed it at the SR80 while holding down one of the buttons on the remote. I watched the LCD screen on the back of the camera for the IR transmitter to light up. It turns out there are two of them, located at the bottom of the unit, and facing the front control surface. If memory serves, they're located right where the Pioneer logo is. Ocassionaly my hand will block them while I'm pushing buttons on the front control surface. Maybe this is the same problem you are having. Hope this helps. -Randy